fix(snack-bar): indicate in afterDismissed whether dismissal was a re…

…sult of an action

Adds a boolean to the `MatSnackBarRef.afterDismissed` result that indicates whether the dismissal came as a result of the user pressing the action button.

Fixes #9147.

src/lib/snack-bar/snack-bar-ref.ts

@@ -11,6 +11,12 @@ import {Observable} from 'rxjs/Observable';
 import {Subject} from 'rxjs/Subject';
 import {MatSnackBarContainer} from './snack-bar-container';
 
+/** Event that is emitted when a snack bar is dismissed. */
+export interface MatSnackBarDismiss {
+  /** Whether the snack bar was dismissied using the action button. */
+  dismissedByAction: boolean;
+}
+
 /**
  * Reference to a snack bar dispatched from the snack bar service.
  */
@@ -25,14 +31,17 @@ export class MatSnackBarRef<T> {
   containerInstance: MatSnackBarContainer;
 
   /** Subject for notifying the user that the snack bar has closed. */
-  private _afterClosed = new Subject<void>();
+  private _afterDismissed = new Subject<MatSnackBarDismiss>();
 
   /** Subject for notifying the user that the snack bar has opened and appeared. */
   private _afterOpened = new Subject<void>();
 
   /** Subject for notifying the user that the snack bar action was called. */
   private _onAction = new Subject<void>();
 
+  /** Whether the snack bar was closed using the action button. */
+  private _dismissedByAction = false;
+
   /**
    * Timeout ID for the duration setTimeout call. Used to clear the timeout if the snackbar is
    * dismissed before the duration passes.
@@ -49,7 +58,7 @@ export class MatSnackBarRef<T> {
 
   /** Dismisses the snack bar. */
   dismiss(): void {
-    if (!this._afterClosed.closed) {
+    if (!this._afterDismissed.closed) {
       this.containerInstance.exit();
     }
     clearTimeout(this._durationTimeoutId);
@@ -58,6 +67,7 @@ export class MatSnackBarRef<T> {
   /** Marks the snackbar action clicked. */
   closeWithAction(): void {
     if (!this._onAction.closed) {
+      this._dismissedByAction = true;
       this._onAction.next();
       this._onAction.complete();
     }
@@ -84,13 +94,16 @@ export class MatSnackBarRef<T> {
       this._onAction.complete();
     }
 
-    this._afterClosed.next();
-    this._afterClosed.complete();
+    this._afterDismissed.next({dismissedByAction: this._dismissedByAction});
+    this._afterDismissed.complete();
+    this._dismissedByAction = false;
   }
 
-  /** Gets an observable that is notified when the snack bar is finished closing. */
-  afterDismissed(): Observable<void> {
-    return this._afterClosed.asObservable();
+  /**
+   * Gets an observable that is notified when the snack bar is finished closing.
+   */
+  afterDismissed(): Observable<MatSnackBarDismiss> {
+    return this._afterDismissed.asObservable();
   }
 
   /** Gets an observable that is notified when the snack bar has opened and appeared. */

src/lib/snack-bar/snack-bar.spec.ts

@@ -307,6 +307,21 @@ describe('MatSnackBar', () => {
     tick(500);
   }));
 
+  it('should indicate in `afterDismissed` whether it was dismissed by an action', fakeAsync(() => {
+    const dismissSpy = jasmine.createSpy('dismiss spy');
+    const snackBarRef = snackBar.open('Some content');
+    viewContainerFixture.detectChanges();
+
+    snackBarRef.afterDismissed().subscribe(dismissSpy);
+
+    snackBarRef.closeWithAction();
+    viewContainerFixture.detectChanges();
+    tick();
+
+    expect(dismissSpy).toHaveBeenCalledWith(jasmine.objectContaining({dismissedByAction: true}));
+    tick(500);
+  }));
+
   it('should complete the onAction stream when not closing via an action', fakeAsync(() => {
     const actionCompleteSpy = jasmine.createSpy('action complete spy');
     const snackBarRef = snackBar.open('Some content');
@@ -489,7 +504,6 @@ describe('MatSnackBar with parent MatSnackBar', () => {
   }));
 });
 
-
 describe('MatSnackBar Positioning', () => {
   let snackBar: MatSnackBar;
   let liveAnnouncer: LiveAnnouncer;